Lamp base



L. C. WERNER Sept. 5, 1961 LAMP BASE Filed Sept. 25, 1958 I. mm \M NN11R Mm m WV c 2 8. E A m i L W F F a a 8 3 FIG. I.

2,999,220 LAMP BASE Leo C. Werner, Cedar Grove, N.J., assignor toWestinghouse Electric Corporation, East Pittsburgh, Pin, a corporationof Pennsylvania Filed Sept. 25, 1958, Ser. No. 763,264 6 Ciaims. (Cl.339-146) This invention relates generally to electric lamps and similardevices and, more particularly, to a base for an electric lamp requiringa multiplicity of end contacts such as the so-called three-light lampfor example.

As is well known, electrical connection with the enclosed filament of anincandescent lamp is achieved by means of lead wires which are sealedthrough the lamp envelope and joined, either by soldering or the like orby mechanical means, to the rim of the base shell and to an insulatedcontactor member such as an eyelet mounted on the end of the shell so asto provide a side and end contact respectively. In the case ofthree-light lamps two end contacts are required in conjunction with theside contact to enable one or both of the filaments to be selectivelyenergized. This is accomplished by forming an annular platform in theouter surface of the insulator between the shell and eyelet and mountinga metal ring thereon to which the appropriate lead wire is attached toprovide an intermediate contactor.

Heretofore, when the lead wires Were soldered or welded to theintermediate and end contactor members sufficient material was fused toform a protruding juncture or terminal which, by virtue of its contour,seated against the socket terminals when the lamp was placed into thesocket fixture. Thus, the fused terminals in such prior art basesconstituted, in fact, the end contacts of the lamp and the heightthereof had to be kept within rather close tolerances not only tocontrol the overall length of the finished lamp but, more importantly asin the case of three-light lamps, to insure that both the end andintermediate contactor terminals seated against and made positivecontact with the corresponding socket elements. As a result, accuratecontrol of the soldering or welding operation was mandatory in order topro duce terminals which were within tolerance thereby making thisoperation a costly and critical one. Effecting the electrical connectionof the lead wires by mechanical means inherently is incapable ofalleviating or solving this problem of criticality insofar as suchtechniques necessarily entail a peening or similar metal-workingoperation which is equally diflicult to control as regards the height ofthe finished terminal. Besides, fused junctures are preferred since theyprovide a more positive and permanent connection.

It is, accordingly, the general object of the present invention toovercome the foregoing deficiencies of and objections to the prior artbase and terminal constructions.

Another object is to obviate the criticality heretofore associated withthe use and fabrication of fused type junctures between the lead Wiresand end contactor members of an electric lamp base.

A further and more specific object of the present invention is theprovision of a base for a three-light incandescent electric lamp whichwill not only permit the lead wires to be soldered or welded to the endcontactor elements but which will facilitate this operation and provideend contact means capable of insuring positive connection with thesocket terminals and aifording more accurate control of the overalldimension of the finished lamp.

The foregoing objects, and others which will become obvious to thoseskilled in the art as the description proceeds, are achieved accordingto the invention by forming outwardly-projecting bosses on theintermediate and end contactor members of a three-light lamp base whichbosses are so conformed and dimensioned that they protrude beyond therespective end surfaces of the base and thus provide preformedaccurately-dimensioned intermediate and end contacts for the lamp. Inorder to insure that the aforesaid objective will be realized in thoseinstances where soldered or welded lead wire terminals are employed, theaforesaid contactor members may also be provided with aninwardly-projecting boss which is apertured to receive the appropriateone of the lead wires and conformed to accommodate a major portion ofthe fused material used to connect said members to the respective leadwires. The outer end surfaces of each of the fused terminals thus formedis accordingly maintained a considerable distance inward from the endsof the outwardly-projecting bosses thereby eliminating any possibilitywhatsoever that the terminals will introduce variations in the overalllamp length or interfere with the seating of all of the aforesaid bossesagainst the socket terminals and the positive contact therewith when thelamp is placed in the socket.

For a better understanding of the invention reference should be had tothe accompanying drawing wherein:

FIG. 1 is an elevational view of a three-light lamp incorporating theinvention;

FIG. 2 is an enlarged plan view of the basal end of the lamp shown inFIG. 1 illustrating in greater detail the character of the intermediateand end contactor members;

FIG. 3 is a fragmentary cross-sectional view through the basal end ofthe lamp along the line IIIIII of FIG. 2, in the direction of thearrows;

FIGS 4 and 5 are perspective views of the intermediate and end contactormembers employed' in the lamp shown in FIGS. 1 to 3;

FIG. 6 is a view corresponding to FIG. 2 but illustrates an alternativeembodiment of the invention; and

FIGS. 7 and 8 are views corresponding to FIGS. 4 and 5 but illustratethe character of the embossments used in the alternative embodimentshown in FIG. 6.

While the invention is broadly applicable to various kinds of electricaldevices which require accurately dimensioned or disposed end contacts,it is particularly adapted for use in conjunction with incandescentlamps, especially those requiring a multiplicity of end contacts such asthree-light lamps for example, and hence has been so illustrated andwillbe so described.

With specific reference to the form of the invention illustrated in thedrawing, in FIG. 1 there is shown a well-known three-light lamp 10which, briefly stated, comprises a sealed envelope 12 containing twofilaments 14 of different wattage rating which are connected to leadwires l5, l6 and 17 and are supported within the envelope by means ofsaid lead wires and a re-entrant glass stem assembly 18 in accordancewith standard lamp-making practice. Two of the lead wires 15 are twistedtogether within the base 20 which is attached to the sealed end of theenvelope l2 and are fastened as by soldering or welding to the rim ofthe threaded base shell 22 to provide a side terminal 414. The remainingleads 16 and 1'7 are separately connected to intermediate and endcontactor members respectively, such as an intermediate contactor ring39 and an apertured disc or so-called eyelet 38 of relatively thin sheetmetm for example, as here shown, which members are of generally planarconfiguration and are attached to but insulated from the bottom of thebase shell 22 by a molded insulator 24 (see FIG. 3). As shown in FIGS. 1to 3, the exterior of said insulator is conventionally contoured toprovide a major and minor extension such as an annular platform 26 andcentrallylocated generally cylindrical lug 28 on which the aforesaidcontactor ring and eyelet, respectively, are mounted. It will also benoted that the platform 26 and lug 28 are terminated on planes which aresubstantially parallel to each other and normal to the lamp axis so thatthe aforesaid intermediate contactor ring 30 and eyelet 38 mountedthereon are similarly disposed and spaced a predetermined distance fromeach other outwardly from the bottom of the base shell 22, as is wellknown. The insulator 24 may be fabricated from glass or a suitablethermosetting plastic, for example, and have openings therethrough suchas passageways 35 and 37 which communicate with the exterior surfaces ofthe platform 26 and lug 28 respectively, as shown in FIG. 3. The fiatend surfaces of the aforesaid platform and lug are so dimensioned thatthe contactor ring and eyelet are substantially coextensive therewith,as shown.

The essence of this invention resides in the configuration of theintermediate contactor ring 36 and end eyelet 38 and in the manner inwhich such configuration is utilized not only to accurately control theoveralblength of the lamp but insure that the lamp will be firmly seatedin positive contact with all of the socket terminals even though theaforesaid contactor elements are soldered or welded to their respectivelead wires and these will be hereinafter described. To this end,portions of the contactor ring 30 intermediate of its edges aredisplaced to provide an outwardly-projecting embossment such as threeradially-spaced dome-shaped bosses 36, as shown in FIG. 1 and moreparticularly in FIGS. 2 to 4. The height and disposition of theaforesaid outwardlyprojecting bosses are such that they define anintermediate contact plane, so to speak, which is substantially parallelto and spaced a definite predetermined distance from the annularplatform 26.

Electrical juncture with the appropriate one of the lead wires 17 isefiected in the conventional manner by threading said lead wire throughthe passageway 35 provided in the insulator 24 and through an aperture31 formed in said ring and then welding or soldering the two elementstogether to form a well-known fused terminal 46, as shown in FIGS. 2 and3. In order to insure that the ends of the outwardly-projecting bosses36 and the intermediate contact plane defined thereby are disposed wellbeyond the outer surface of the fused terminal 46, the portion of thecontactor ring 30 immediately adjacent the aperture 31 therein isdisplaced and flared in wardly to provide an inwardly-projectingdome-shaped boss 34 (FIGS. 3 and 4). In this manner a well or recess isprovided which accommodates the major portion of the fusedelectrically-conductive material used to form the terminal 46 therebymaterially reducing the exposed height of said terminal and achievingthe aforesaid objective, as shown most particularly in FIG. 3. Asillustrated, the lead wire 17 is of such length that the end thereof iscompletely embedded within the filling of fused material in theinwardly-projecting boss 34 so that the terminal 46 is substantiallyflush with the outer surface of the contactor ring 30.

As shown in FIG. 4, the contactor ring 30 is provided with a centralopening 32 of slightly smaller diameter than the root diameter of thelug 28 so as to be firmly anchored in the insulating material, as iswell known.

The end eyelet 38 is also provided according to the invention with aplurality of outwardly-projecting domeshaped bosses 42 and an aperturedinwardly-projecting boss 46. In this instance, however, theinwardly-projecting boss 40 and aperture 41 therein arecentrally-located so that said aperture communicates with thecentrallylocated passageway 37 in the insulator lug 28, and fouroutwardly-projecting bosses 42 are employed and radially spaced atapproximately equal distances around the eyelet, as illustrated mostclearly in FIGS. 2 and 5. As in the case of the intermediate contactorring 30 abovedescribed, the apertured inwardly-projecting boss 40receives a lead wire 16 and a filling of fused electricallyconductivematerial to provide a recessed end terminal 48 which is substantiallyflush with the outer face of the eyelet 38, and the outwardly-projectingbosses 42 are dimensioned to define an end contact plane which issubstantially parallel to and spaced a definite predetermined distancefrom the end face of the lug 28. Insofar as the outer surfaces of theplatform 26 and lug 28 are precisely spaced one from another as anatural consequence of the molding of the insulator 24, the intermediateand end contact planes defined by the outwardly-projecting bosses 36 and42 respectively are substantially parallel to each other and spacedapart a definite predetermined distance d, as shown in FIGS. 1 and 3,which distance will remain constant from lamp to lamp since it isgoverned by preformed portions of the ring 30 and eyelet 38 rather thanby the fused terminals 46 and 48 as was the case heretofore.

The contactor ring 30 and eyelet 38 may be conveniently fabricated fromsheet brass or other suitable thin metal material by well known stampingtechniques.

While in accordance with the above-described embodiment of the inventiona plurality of outwardly-projecting bosses have been employed to defineaccurately and consistently spaced contact planes, the same result maybe obtained by providing only one such boss on each of the contactormembers. While this latter arrangement will not define planes ofcontact, the end result will still be the same insofar as thelongitudinal distance between the ends of the contact bosess will againbe precisely controlled and kept constant from lamp to lamp and it isthis relationship which is essential and achieves the desired objective.

Alternatively, instead of discrete portions of the contactor membersbeing displaced a ring 30a may be provided wherein a continuous C-shapedembossment 50 is provided which extends from a point adjacent one sideof the apertured inwardly-projecting boss 34a around said ring to apoint on the opposite side of said boss, as shown in FIG. 7. In likemanner, an eyelet 38a may be provided having an annular ernbossrnent 52spaced from and concentric with a centrally-disposed inwardlyprojectingboss 40a and aperture 41a, as shown in FIG. 8. As will be noted in FIG.6, with this arrangement the C-shaped embossment 50, annular embossment52 and fused end terminal 48a are disposed in spaced concentricrelationship with each other and the base shell 22a when the ring 30aandeyelet 38a are mounted in their assem bled positions on the insulatorplatform 26a and lug 28a respectively of the base 20a.

While the invention as hereinbefore described has been considered interms of a multiple contact lamp base, an eyelet having inwardly andoutwardly-projecting bosses conformed in accordance with the foregoingprinciples of the invention may also be advantageously utilized as theend contactor member for a single-filament lamp since it would not onlyafford more accurate control of the overall lamp length but alsofacilitate the soldering or welding of the lead wire and provide acontact surface which would inherently remain free of oxidation andpresent a neat appearance.

As will be appreciated from the foregoing, the objects of the inventionhave been achieved by providing a lamp base which, by virtue of theconfiguration of its end contactor members, not only insures positiveconnection with the corresponding socket terminals but permits and evenfacilitates the soldering or welding of the lead wires to said contactormembers.

While several embodiments of this invention have been described indetail in accordance with the patent statutes, it will be understoodthat various modifications in the configuration and arrangement of partsmay be made without departing from the spirit and scope of theinvention.

I claim:

1. A multiple-contact base comprising, a shell, aninsulator attached toand projecting beyond an end of said shell and contoured to provide twoextensions of unequal length, a first contactor member of generallyplanar configuration mounted on one of said extensions and located at afirst plane that is spaced from the end of said shell and is transverseto the shell axis, and a second contactor member of generally planarconfiguration mounted on the other of said extensions at a secondtransverse plane located beyond said first plane, said first and secondcontactor members each comprising a sheet-metal element a portionwhereof is displaced to form at least one outwardly-projecting boss ofsufiicient axial length to provide preformed contact surfaces that arespaced predetermined fixed distances from the end of said shell and fromeach other.

2. A multiple-contact base as set forth in claim 1 wherein, otherportions of said first and second sheet-metal contactor members aredisplaced in the opposite direction to provide an inwardly-projectingboss having a lead-wire aperture therein, and said insulator is providedwith lead-wire passageways that communicate with said apertures.

3. A multiple-contact base as set forth in claim 1 wherein the displacedportions of each of said first and second sheet-metal contactor membersform a plurality of outwardly-projecting bosses that define a contactplane spaced a predetermined fixed distance from the end of said shell.

4. A multiple-contact base comprising, a shell, an insulator attached toand projecting beyond an end of said shell and contoured to provide twoextensions of unequal length, a first contactor member of generallyplanar configuration mounted on one of said extensions and located at afirst plane that is spaced from the end of said shell and is transverseto the shell axis, and a second contactor member of generally planarconfiguration mounted on the other of said extensions at a secondtransverse plane located beyond said first plane, said first and secondcontactor members respectively comprising a ring and disc wardly fromsaid annular platform, and wherein an intermediate contactor element andan end contactor element of sheet metal and generally planarconfiguration are mounted on said annular platform and on the end ofsaid extension respectively, the improvement comprising at least oneoutwardly-projecting boss on said intermediate and end contactorelements defined by displaced portions thereof and located anddimensioned to constitute pre formed contact surfaces that are spacedpredetermined fixed distances axially from the end of said shell andfrom each other.

6. In an electrical connector of the type adapted to be inserted into asocket or the like, first and second contact means, and a body ofinsulating material attached to the body portion of said electricalconnector and holding said first and second contact means in spacedapart electrically-isolated relationship at the end of said connector,each of said contact means comprising a sheet-metal contactor member ofgenerally planar configuration having an aperture therein and a portionthat is displaced and defines at least one outwardly-projecting bossthat axially extends a predetermined distance beyond the outer face ofthe respective contactor members, a conductor connected to each of saidcontactor members and extending through said insulating body, the outerends of said conductors being disposed in the aperture in the respectiveones of said contactor members and joined to said members by a quantityof fused metal that extends to the outer face of said members andconstitutes an exposed terminal thereat, said outwardly-projectingbosses extending beyond the associated ones of said terminals andthereby constituting preformed contact surfaces for said electricalconnector that are spaced a predetermined fixed distance from the endthereof and from each other.

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